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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"Steric repulsion"”.
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Interfacial behavior of RNA-free MS2 bacteriophage particles
… ionic strength suggests an important role of steric repulsion. Using a Quartz Crystal Microbalance, RNA-free MS2 attachment efficiency was found to be higher than MS2. This can be explained by more steric repulsion by the untreated MS2 particles. Similarity in electrophoretic mobility and …
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REDUCTIVE ELIMINATION OF (DPMS)PTIV COMPLEXES DERIVED FROM ISOMERIC 2-BUTENEs AND 2-BUTYNE (DPMS=DI(2-PYRIDYL)METHANE SULFONATE)
… may be involved in these reactions and that steric repulsion between substituents at the oxetane carbon atoms may play a major role in determining the predominant of the two competing mechanisms. Platinum(IV) η1-butanone complex was synthesized and characterized, which was found to undergo …
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Roles of surface interaction on Cryptosporidium parvum oocyst transport in subsurface environment
… was essential to van der Waals interaction and steric repulsion between oocyst and quartz surfaces. RSPF experiments illustrated that steric repulsion caused by oocyst surface macromolecules prevented oocyst deposition at higher ionic strength where the Derjaguin–Landau–Verwey–Overbeek (DLVO) …
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A Computational Analysis of Supported and Unsupported Group 6 Transition Metal-Metal Bonds Based on the Natural Orbitals for Chemical Valence (NOCV) and the Extended Transition State (ETS) Techniques
… a trend that is influenced largely by the higher steric repulsion between metal fragments that diminish down the triand with increasing M-M distances. The five bonding components of the putative Cr-Cr quintuple (σ2,π2,π´2,δ2,δ´2) bond in Ar´CrCrAr´ (Ar´=C6H3-2,6(C6H3-2,6-Pri2)2) are also presented …
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Synthesis and Characterization of Surface-Functionalized Magnetic Polylactide Nanospheres
… extended into the dichloromethane and provided steric repulsion between the magnetite-polymer complexes. The resultant magnetite-polymer complexes were further incorporated into controlled-size nanospheres. The complexes were blended with poly(ethylene oxide-b-D,L-lactide) diblock copolymers to …
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Bottlebrush Polymers: A Pathway to Engineering Surfaces and Interfaces
… and densely-grafted polymeric side-chains. Steric repulsion between the side chains forces the backbone to extend, leading to a rod or wormlike conformation. Therefore, bottlebrush polymers resemble both comb polymers and polymer-grafted particles. Our goal is to develop an in-depth …
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The Development of a Per-O-Benzylated 1-C-Aryl-glycal for the Synthesis of Kdo Glycosides
… top face of the glycal therefore directing via steric repulsion the formation of a the beta-Kdo glycoside. The goal of this thesis was to exchange the fused isopropylidene rings on the glycal with acyclic protecting groups so as to test if glycosylation results could be made to favor formation …
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Gold Nanomaterial–Biomolecule Interactions: Influence of Size, Gold Nanomaterial–Biomolecule Interactions: Influence of Size, Surface Chemistry, and Environment Surface Chemistry, and Environment
… was reversed in the presence of BSA because of steric repulsion between BSA-coated nanoparticles. Further, circular dichroism and ToF-SIMS indicated that BSA largely retained its secondary structure upon adsorption on the AuNPs. Collectively, these findings advance the mechanistic understanding …
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Synthesis and Characterization of Polylactide-siloxane Block Copolymers as Magnetite Nanoparticle Dispersion Stabilizers
… extended into the dichloromethane and provided steric repulsion between the magnetite-polymer complexes.
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Correlations between MO Eigenvectors and the Thermochemistry of Simple Organic Molecules, Related to Empirical Bond Additivity Schemes
… can be achieved using bondingness with a simple steric repulsion term (SSR) in a bond additivity scheme, and a standard deviation of 5.2 kJ mol 1 can be achieved using a Lennard-Jones potential. The method is compared with the group method of Pedley, which for a slightly smaller set of 338 …
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Synthesis of Bottlebrush Polymers Using the Grafting-Through and Transfer-To Methods
… nature of bottlebrush polymers results in steric repulsion between neighboring polymer chains, forcing these macromolecules to adopt a chain-extended conformation. Although these remarkable macromolecules have a many different applications, the transformative potential of the bottlebrush …
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Rotavirus interactions with silica and natural organic matter
… suggest ionic hydrogen bond-based and electrosteric-based interactions as major mechanism between rotavirus-CRW and rotavirus-SRNOM, respectively. Besides electrostatics, results from this study suggest that steric repulsion, acid-base interactions, and divalent cation complexation with …
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Synthesis and Characterization of Complex Polymer Topologies using Ring-Opening Metathesis Polymerization
… polymers' densely bonded structure causes steric repulsion between nearby polymer chains, leading them to exhibit a chain-extended conformation. Even though these extraordinary macromolecules have several uses, the transformational promise of the bottlebrush polymer architecture has yet to …
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Studies Related to the Alternating Copolymerization of Substituted Stilbenes
… unusual rigidity to the polymer backbone due to steric repulsion. By functionalizing stilbene, a variety of functional groups and ionic groups can be precisely placed along the polymer chain with tunable charge density. Therefore, stilbene containing polymers are potentially rod-like …
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Hydrophobic Forces in Free Thin Films of Water in the Presence and Absence of Surfactants
… These non-DLVO forces may be attributed to the steric repulsion between asphaltenes extracted on the bitumen surface. The steric forces increased with pH and temperature, which may be explained by the increased solubilization of asphaltenes in water. The steric force also increased with …
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Preparation of emulsifiers from pea and corn starches using octenyl succinic anhydride modification
… emulsions during 28-day storage at 4°C due to steric hindrance and electrostatic repulsion provided by the emulsifier layer on the droplets. However, the droplet sizes of all the OS-PS emulsions increased to some extents during the storage, suggesting the least stability of these emulsions. …
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The Surface Charge of Soft and Hard Sphere Colloidal Particles - Experimental Investigation and Comparison to Theory
… with the surface forces apparatus. We found that steric repulsion does not occur. The repulsion only arises from residual charges inside the brush layers. From the resulting force curves we were able to deduce an interaction profile of SPB particles in aqueous solution containing multivalent …
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Smart organic-inorganic nanohybrids of functionalized silsesquioxane nanoparticles
… micellar core and the compensation of increased steric repulsion due to complexation and attractive interactions between the silsesquioxane nanoparticle and the charged PAA. The maximum of the interaction at 0.1 M NaCl could be deduced to be in the range 3.5 < pH < 7.5 NaCl. At low salinity (0.01 …
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Fine���tuning the reduction potential of Cupredoxin proteins by altering secondary coordination sphere interactions
… methods. As such, hydrogen bonding, steric repulsion and loop torsion were used in attempts to alter the backbone carbonyl and investigate its electronic contribution to the copper site. It was seen that this region of the protein, and presumably the carbonyl oxygen itself, does have …